A recent study published in the journal Scientific Reports appears to establish a link between certain genetic factors relating to eye color and skin pigmentation, and the risk for uveal melanoma.
Uveal melanoma (UM) is the most common primary adult intraocular cancer involving the vascular layer within the eye between the retina and the sclera. Researchers have long suspected that people with light pigmentation and blue eyes have an increased risk of developing this type of eye cancer. Previous studies show that about 12% of uveal melanoma manifest within family circles, often involving a variety of other cancers including skin cancer. The co-occurrence of skin cancer and UM within some families suggests a shared predisposition to both types of cancer.
But despite the suspicion that there are genetic risk factors involved in uveal melanoma, there has been little solid research establishing a firm link.
To study the possibility, researchers at the Perlmutter Cancer Center of the New York University School of Medicine selected 28 genetically based variations (SNPs) found within a given population of people. SNP variations have been shown to underly differences in susceptibility to diseases (such as sickle-cell anemia and cystic fibrosis) within different groups of people.
For the study, researchers conducted association analysis using 272 UM patients and 760 controls of European ancestry. Focusing on SNPs associated with skin cancer and related characteristics (including skin and eye pigmentation), they found five variants significantly associated with UM risk. In a nutshell, the study provides evidence that there is a link between light skin pigmentation (and blue eyes) and uveal melanoma:
“The identification of novel germline genetic loci involved in UM susceptibility in our study provides the first evidence of a link between the inherited genetics of pigmentation and UM risk. It has been established that lighter pigmentation and chronic sun exposure impact the development of choroid nevi, which occur in ~7% of the US population and are a known precursor for UM. Testing the associations in this study in the context of UM risk and the presence of ocular nevi will also be important in future analyses… Importantly, these genetic observations are also in clear alignment with previous epidemiological studies demonstrating that light eye color is indeed a UM risk factor.”
The association between skin cancer, uveal melanoma, and the emerging evidence of some genetic predisposition for the development of uveal melanoma underscores the importance of fair-skinned people protecting their eyes from sun exposure just like they do their skin. Since you can’t rub suntan lotion on your eyeballs, it’s important to wear sunglasses that provide 100% UV protection. Think of sunglasses as sunblock for your eyes. In fact, it’s a good idea for everybody to wear UV-cancelling sunglasses to protect their eyes from dangerous ultra-violet light rays.